Over the past few years, the dramatic increase in energy cost and dire predictions of future shortages and upward spiralling energy prices have focused much attention on the need to conserve our present energy resources while developing additional sources for the future. A significant effort within the conservation movement has been centered on designing machines and heating and cooling systems that operate more efficiently. Evidence of the success of such efforts can be found in the increased milage for automobiles and various energy-saving features incorporated in new appliances and machines. Nevertheless, countless machines and heating and cooling systems not incorporating these energy saving features are currently in service and have useful lives extending well into the future. Thus, if such machines and systems can be retrofitted with devices to increase their efficiency or to make use of otherwise wasted energy, the conservation movement will be further promoted.
For example, refrigeration systems, as a general rule, dissipate the heat withdrawn from the medium to be cooled and the compression energy added to the refrigerant gas into the ambient atmosphere. In the past, there have been attempts to recover this wasted heat from the discharge side of the refrigeration systems. Oftentimes, a heat exchanger has been included as an integral part of the refrigeration system as a means for heating another medium. On the whole, these efforts have been unsuccessful because low energy prices have made it economically more feasible to use energy inefficiently than to increase the capital investment in a refrigeration system by including a heat recovery system. Also, many of the heat recovery systems have been inefficient and have boosted the expense of maintaining the refrigeration systems. Thus, there are numerous refrigeration systems in current use that continuously discharge useful energy into the ambient atmosphere, energy which could readily be used to heat, for example, cold water for use as boiler feed water, wash water, etc.